1. A D. subordinating conjunction <span>introduces a dependent clause in a complex sentence.
2. The pronoun <em>which </em>is used as a D. interrogative pronoun.
3. The number of subordinate clauses is - D. one subordinate clause only. </span>
Answer:
formal........................
A parallel sentence mentions the same grammatical expression twice. I would go with "D". 'Passed' and 'Demonstrated' are both past tense words that express the same past tense grammatical idea.
If you have more questions, feel free to ask me.
